Commercial vehicles have pneumatic brake systems that are linked to electronically controlled functions in order to improve safety. Herein, the overall system is referred to as an electropneumatic brake system. A stipulated constituent part of brake systems in commercial vehicles is an anti-lock function in many countries.
The anti-lock function can be realized in different ways. In one simple embodiment for two axles, the rotational speeds of the wheels of the two axles are detected. Each wheel is assigned a rotational speed sensor, and each axle is assigned a dedicated modulator with a control unit. Each axle is therefore a constituent part of what is known as a 2S1M configuration. Towed vehicles with a 2S1M configuration on each axle are ubiquitous in the United States.
Somewhat more precise regulation is possible by way of more complicated systems, for example in a 4S3M configuration. In this configuration, four rotational speed sensors on two axles interact via a common control unit with three modulators. This type of configuration is relatively complex, however.
In addition to the antilock function, the electropneumatic brake system cart have further functions—for example, to solve a particular set problem for towed vehicles, in particular drawbar trailers. If a towed vehicle navigates a band in the roadway too rapidly, the towed vehicle can turn over and drag the towing vehicle or the tractor vehicle with it or can become detached therefrom. In such a situation, the driver may notice the tipping process too late—namely, not until the driving behavior of the traction engine is affected.
In order to avoid situations in which the towed vehicle threatens to turn over, an additional stability function can be integrated into the brake system. Applicant provides a known electronic brake system (EBS) with an additional stability function, namely, what is known as roll stability support (RSS). A current stability factor is calculated continuously by e stability function on the basis of the available data. As soon as a limiting value is exceeded, the towed vehicle is braked automatically by way of the stability system until a non-critical speed is undershot. Instead of the stability function or in addition thereto, other functions can also supplement the anti-lock function.